The present invention relates generally to a system for mining coal in underground mines wherein a drilling unit bores horizontal holes into a coal seam and a retrieval unit extracts auger flights from a previously drilled hole simultaneously and in conjunction with the drilling unit.
In the prior art and in the present invention auger mining machines of this type comprise an auger embodying a cutting head suitable to the thickness of the coal seam connected to and rotatably driven by a string of end connected, helixally veined auger sections driven from the machine by being rotated and urged longitudinally of the auger. The cutting head penetrates the coal seam and the mine coal is transported rearwardly from the cutting head along the auger string by the veins of the auger sections out of the hole cut by the cutting head to a conveyor which carries the coal away from the machine. As the cutting head is caused to penetrate into the hole, it is necessary to introduce auger sections into the string until the desired length of the auger string is reached to achieve the desired depth of the hole. After the cutting head has penetrated to the desired depth of the hole it must be withdrawn by removing auger sections until the cutting head is out of the hole. The machine as a whole is then moved laterally to another position where its auger can drill another hole generally parallel to the previously drilled hole. Heretofore the prior art has disclosed patents for various augers and systems for the mining of coal. Some of the patents of the prior art are listed as follows:
U.S. Pat. No. 3,682,261 Michael J. Bird, Aug. 8, 1972
U.S. Pat. No. 2,846,093 Neil W. Densmore, Aug. 5, 1958
U.S. Pat. No. 3,281,187 G. L. Adams, et al., Oct. 27, 1966
U.S. Pat. No. 5,695,016 Ronald C. Deeter, et al., Dec. 9, 1997
U.S. Pat. No. 3,698,768 John L. Delli-Gatti, Oct. 17, 1972
U.S. Pat. No. 4,264,106 Ronald C. Deeter, et al., Apr. 28, 1981
Typically, in the underground mining of coal a roadway is created in the mine of predetermined limited height and width and thus, the size and height of the augering apparatus becomes critical and the retrieval and storage of auger flights presents a storage problem. Heretofore, in augering machines for mining coal in underground mines a series of relatively deep parallel horizontal holes are drilled in the coal seam and when the drilling of one hole is completed the augering machine is moved over the mine floor to a next adjacent position for drilling an adjacent parallel hole. The auger drill string is detached from the chuck of the boring machine prior to the shifting of the machine to its new drilling position and the series of auger drill flights are stored in the completed hole or on the floor of the roadway until needed for use in the drilling of the next adjacent hole. The auger flights are transferred a section at a time for connection to the drill string during drilling of the adjacent hole. It has become customary practice to roll the heavy auger sections over the rough bottom or floor of the mine and to lift manually and rotate the auger sections to bring them in proper alignment with the drill chuck to enable attachment thereof to the drill string as the adjacent hole deepens. In some instances a string of auger flights is stored in the previous drilled hole and requires the use of a separate apparatus to retrieve and transfer the auger flights to the auger machine for use in drilling the next adjacent hole. Such a transfer mechanism for auger drills is disclosed in U.S. Pat. No. 2,846,093 issued to Neil W. Densmore on Aug. 5, 1958.
One object of the present invention is to provide a new and improved underground auger system comprising a drilling unit and a retrieval unit which are adjustably connected and provide for the continuous drilling of holes and simultaneous retrieval of auger flights from a previous drilled hole, thus increasing efficiency in the mining of the coal and more efficient storage and transfer of auger flights to the drilling unit. In addition, the drilling unit and retrieval unit are coupled in front and back preferably with dog-bone type connectors which assures consistent pillar widths (the center to center distance of the auger holes) and closer coupling distances and also reduces the stress induced into each unit""s frame in the event of uneven alignment. The dog-bone connectors are interchangeable to allow adjustments to pillar widths and assure the drive chains of the drill unit and retrieval unit are parallel during operation.
U.S. Pat. No. 3,682,261 issued to Michael J. Bird on Aug. 8, 1972, discloses a tunnel boring machine with a carriage which slides along a track and the carriage includes a spindle for attachment to a boring auger and a power supply which drives the spindle and also drives an hydraulic ram which moves the carriage along the track. A winch assembly is also provided in conjunction with the spindle for retracting auger sections from the bored tunnel without moving the carriage. The invention does not provide or teach of an underground auger system comprising a drilling unit and retrieving unit which are adjustably connected and work simultaneously with each other.
Further, the present invention provides a crowd mechanism within the drill unit for movement of the carriage and results in crowding forward in connect ion with the rotation of the cutting head and gives the cutting head the ability to dig the bits into the coal seam and cut. The crowd mechanism comprises a chain and sprocket system coupled to hydraulic cylinders which gives a mechanical disadvantage, however, it allows the carriage to move twice the distance of the cylinder stroke. Guide bars keep the sprocket from wandering off of a track and reduces wear on the cylinder seals. Two hydraulic cylinders are used for moving the carriage in each direction (four per unit) and thread adjustments are provided under the carriage to allow adjustment for cylinder differences and chain wear. A second crowd mechanism is provided within the retrieval unit and comprises the same component parts and provides for the movement of the carriage forward and backward and with the rotation of the drive unit gives the string of auger flights the ability to rotate out of the drilled hole. Prior art does not teach or disclose crowd mechanisms with respect to drilling units or retrieving units.
U.S. Pat. No. 3,698,768 issued to John L. Delli-Gatti on Oct. 17, 1972, provides an augering machine which includes an auger string composed of a plurality of auger flights connected to each other and at the rearward of the string a rotary drive means. The connection of the auger flights is by means of a pin and socket joint and includes a locking means and an unlocking member. Typically, in the industry auger flights are provided with a male and female end with the male end adapted to fit the female end of another auger flight and a spring-loaded latch pin is provided to secure two auger flights together and allowing the removal from the drilled hole without coming apart. In removing auger flights from the hole it is necessary to disconnect each auger flight from the string of auger flights for storage and transferring the auger flights to the drilling unit. The present invention provides a front delatch mechanism disposed within the drill unit and retrieval unit which comprises a hydraulic cylinder, bar linkage, and a spring-loaded latch actuator bar and provides a new and improved means of lifting the latch pin on the auger flight to provide for disconnecting of each auger flight from the string upon their removal from the drilled hole. The prior art does not teach or disclose of such a front delatch mechanism.
The present invention further provides for a transfer arm located within the retrieval unit to move auger flights from a belly pan in the retrieval unit to a belly pan in the drill unit during operation and it also is used to move auger flights to and from a staging rack in the retrieval unit to the belly pans of the drill and retrieval units. The transfer arm comprises a telescoping arm attached pivotally to the retrieval unit at one end and with a fork at the other end to cradle the auger flights when lifting and moving the flights. Hydraulic cylinders are provided to raise and lower the transfer arm and to extend and retract the arm. A transfer arm is not disclosed or taught in any prior art.
Another object of the present invention is to provide a staging rack area disposed within the retrieval unit to allow for the loading, unloading, and storage of auger flights within the retrieval unit and to allow the auger flights to be moved to and from the belly pan in the retrieval unit and further to allow the auger flights to be ready and available to be picked up by the transfer arm. In operation the auger flights may be moved to and from the retrieval unit and the drilling unit by the transfer arm and may be moved to and from the belly pan of the retrieval unit to the staging rack allowing for great flexibility in locating the auger flights for each stage of operation. A drive cross shaft with sprockets at each end driven by a power source is provided together with a second set of sprockets, shaft, and transfer chains with rollers to move the auger flights to and from the storage area and the belly pan within the retrieval unit. The transfer chains are synchronized and chain attachments, side guides, adjustment means, and stops are provided to prevent the auger flights from rolling and twisting during movement and to insure proper alignment of the auger flights.
The present invention further provides leveling jacks and skids in the drill unit and the retrieval unit to facilitate moving the machine and setting the angle for extracting flights from previously drilled holes. Roof jacks are also provided with each unit to work in conjunction with the leveling jacks and skids to wedge the units between the roof and floor of the mine roadway providing stability during extracting and drilling operations.
Prior art discloses and teaches of various auger mining machines and retrieval and storage apparatus for auger flights. U.S. Pat. No. 3,281,187 issued to George L. Adams, et al. on Oct. 25, 1966, discloses and teaches of a dual augering mining machine with dual auger storage racks but does not provide or teach of an underground auger system such as the present invention with a drill unit and a retrieval unit which are adjustably connected and provide for the simultaneous drilling and removal of auger flights or of a transfer arm mechanism, staging rack, crowd mechanism and delatch mechanism as are provided in the present invention. Further U.S. Pat. No. 4,264,106 issued on Apr. 28, 1981, to Ronald C. Deeter, one of the inventors of the present invention, discloses an augering machine which embodies jacks and skids which permit ready maneuverability of the machine and a cross conveyor for conducting away mined material from the auger string which are also provided in the present invention. However, the invention does not provide or teach of an underground auger system comprising a drill unit adjustably connected with a retrieval unit, crowd mechanism, staging rack, transfer arm mechanism, or delatch mechanism as are provided in the present invention.